Source : Webster's Revised Unabridged Dictionary (1913)

Osages \O*sa"ges\, n. pl.; sing. {Osage}. (Ethnol.)
   A tribe of southern Sioux Indians, now living in the Indian
   Territory.

Source : WordNet®

Osage
     n 1: a member of the Siouan people formerly living in Missouri in
          the valleys of the Missouri and Osage rivers; oil was
          found on Osage lands early in the 20th century
     2: a river in Missouri that is a tributary of the Missouri
        River [syn: {Osage River}]
     3: the Dhegiha dialect spoken by the Osage people